My objections to edition wars (and similar things) have always been that they tend to drown out more useful critiques. So, somewhat contra pawsplay's earlier assertion, there have been useful criticisms of 4E--even heated, useful ones. If one poked around a bit, one could easily find them. There is one going on right now on the 4E board, and near as I can tell, all of the participants are generally pro-4E. However, there have also been a lot of sturm and drang over very poor criticisms, very poorly and
repeatedly expressed. If those tend to register more strongly in some memories than others, I suggest a sample bias.
And just to be clear, I saw exactly the same thing with the 3E and 3.5. It seemed you couldn't have a decent discussion about 3E skills for five minutes in late 2000, without some bloke interrupting with how the monk/wizard multiclass was completely broken and anathema to everything that D&D stood for!
Though I'll grant that I'm in a distinct majority when it comes to criticism. As far as I'm concerned, design criticism is about discerning the intent of the designer, and then seeing how well the design is realized. While not entirely objective, it can have objective moments. Pemerton's discussion of RM above is one such example.
It seems to me that a lot of criticism, however, is founded on, "your design intent sucked; so sucks to be you." Not that anyone has to like something, merely because the design intent and implementation are well matched. I certainly don't always, and some things I've quite enjoyed have been rather poorly designed, when it comes to it. But I have found that the "sucks to be you" school of criticism does tend to blur the lines between what works versus what the speaker likes--frequently with the aforementioned symptom of making a lot of noise that drowns out the more pointed and useful criticisms. Not always, but often. (Every now and then, someone consciously takes a more holistic approach on the criticism of the design intent, and because it is conscious, does it well.)